When we where working on engines, we noticed that very often the bearing fittings where: not round, and often out of dimensions.
We decided to rework the fittings from the crankshaft.
We rebored the old fittings and crimp newly made aluminum bushes in them.
The results where astonishing!
The cranck now runs around in its new bearings almost without any friction.

Advantages:

The motor will run, better on idle.
The engine will give more power due to the lesser friction from the crank.
Longer bearing life.
Smoother running.